Kingstown



' UNITED STATES PATENT ()FFICE.

HENRY HASWELL HEAD, OF DUBLIN, AND LLEWVELLYN SAUNDERSON, OF KINGSTOWN, COUNTY OF DUBLIN, IRELAND; SAID HEAD ASSIGNOR TO SAID SAUNDERSON.

CARBON FOR ELECTRIC LAMPS.-

SIPECIFIGATION forming part of Letters Patent No. 422,302,11ated February 25, 1890.

Application filed May 15, 1889. Serial No. 310,888. (No specimens.)

To all whom it may concern: sium, rubidium, potassium, or any of their Be it known that we, HENRY HASWELL salts, according to the light required. The HEAD, residing at 17 Fitz William Square, whole, after careful mixing, is introducedinto Dublin, Ireland, and LLEWELLYN SAUNDER- an iron mold and heated under pressure, first SON, residing at De Vesci Terrace, Kingsgently, but finally very strongly. The cartown, county Dublin, Ireland, subjects of the hon rods so made, if found too porous, are Queen of Great Britain,jointly have invented heated and introduced into hot coal-tar, and. certain new and useful Improvements in the the whole heated for some time, preferably in Manufacture of Oarbons for Electric Lamps, a vacuum. The carbon rod is then taken out 10 of which the following is a specification. and its surface cleaned. It is then introduced Ourinvention relates especially to improveinto another. mold and again heated under ments of the composition of the carbons for pressure. These operations are repeated unthe purpose of improving the color of the light til the required density is obtained. emitted therefrom. For some purposes, in order to render the I 5 In order to carry out our invention, we effect more satisfactory, the outer portion of manufacture the carbons from a mixture of the carbon rod should contain no fusible colpowdered gas-coke, coking-coal, an infusible' oring-bodies. When this is the case, hollow or difficult-ly-fusible material, and a material carbon rods are made. from the mixture of to vary the color of the light, and heat the coke, coal, and refractory substances other 20 mixture under pressure in a mold. than the coloring materials by introducing The subject-matter of our invention is spethe mixture into proper molds and treating cifically designated in the claims at the end under pressure, as hereinbefore described. of this specification. The hollow carbon so made is then filled with The manner of manufacturing the carbons a mixture of from thirty to fifty parts of powis as follows: In order to make a compact dered anthracite or coke, ten to twenty parts coke difiicult to burn, powdered gas coke of powdered coal, and one to twenty parts of is mixed with powdered coking coal in the calp limestone, or one of the above-named reproportion of coke varying from eighty per fractory bodies and one to twenty parts of one cent. to fifty per cent, the coal varying from of the above-named salts or a mixture thereof.

30 twenty per cent. to fifty per cent. To this The carbons are then again-heated as before. mixture is added one per cent. to ten per cent. \Ve are aware that it has been proposed to of one of the following infusible or difficultlymake electric-light carbons of powdered coke, fusible substances namely, glass, silica, cycoal, and a difficultly-fusible material, and do anite, kaolin, bauxite, asbestus,pumice, feldnot broadly claim such a carbon.

3 5 spar, gadolinite, samarskite, zircon,limestone, We are also aware that a carbon pencil condolomite, witherite, phosphate of lime, stronsisting of a metallic tube covered with pure tianite,braunite, titanic iron, chromeiron ore, carbon and inclosing material for coloring or wolfram,molybdenite, fiuor-spar, cerite, cryoincreasing the light'is old; but, so far as we lite, phosphate of aluminum, magnesite, or are aware, we are the first to use carbons com- 40 compounds of nickel and cobalt. This mixbining integrally coke, coal, a refractory non- 9o ture forms the groundwork of the carbon, and coloring material, and a coloring material, these substances are used in order to make and also the first to use a hollow carbon comthe impurities in the above-named mixture posed integrally and entirely of the threefirstdifficult to fuse, and hence increase the innamed ingredients with material for coloring 45 tensity and steadiness of the light. To the the light inclosed therein. 5 above-mentioned mixture is then added one hat we claim as new and as of our own per cent. to twenty per cent. of one of the folinvention is= lowing bodies or mixtures thereof namely, 1. The herein described carbon pencil for sodium, lithium, strontium, calcium, copper, electric lights, made from a compressed mix 5o thallium, barium, indium, lead, boron, one ture of from eighty per cent. to fifty per cent.

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of powdered gas-coke, from twenty per cent. to fifty per cent. of powdered coal, from one per cent. to ten per cent. of refractory material, and from one per cent. to twenty per cent. of coloring-matten 2. The herein-described carbon pencil for electric lights, made from a compressed mixture of from eighty per cent. to fifty per cent. of powdered gas-coke, from twenty per cent. to fifty per cent. of powdered coal, from one per cent. to ten per cent. of refractory material, from one per cent. to twenty per cent. of coloring matter, all intimately mixed, and coal-tar applied to and impregnating the surface of the carbon.

3. The herein-described carbon pencil for electric lights, consisting of a hollow or tubu- HENRY HASVELL HEAD.

LLEVVELLYN SAUNDERSON.

Witnesses:

MAURICE S1. J. Ross, A. WM. LABERTOUOHE,

Not. Pub, Dublin. 

